Abstract:

Twenty-one flowering time genes were found in Arabidopsis. To search out the corresponding homologous genes in nectarine，NCBI blast analysis was carried out. Twenty-one genes were classified into two groups of flowering promotor or inhibitor based on mutatant phenotype and annotation functions in Arabidopsis. We use seven-year-old‘Shuguang’nectarine flower buds as material and then define the period of dormancy including dormancy induction period，endo-dormancy and dormancy-release based on germination rate which measured by hydroponics. The results showed that the average weight per bud was a trend of steady in dormancy induction period and endo-dormancy and  then suddenly increased to 0.12 g after dormancy-release. The average weight per bud added up to maximum equal to 0.15 g in next year February 9. The water content of flower bud began to slowly fall from endo-dormancy to dormancy-release and reached the lowest level with the water content of 39% in dormancy-release. Later the water content of flower bud has risen steadily to 53%. Clustering analysis found that two types of gene expression pattern in dormancy process and the effect of genes on the flowering does not exist inevitable correlation. Furthermore，the gene expression patterns of the nectarine flower buds were analyzed during the period of dormancy（endo-dormancy and dormancy-release）by RT-PCR and the results were as follows. The expression of PpFT-like and PpCO-like were gradually increased，so they may be associated with chilling requirement accumulation. In addition，the expression of PpLSD1-like，PpFCA-like，PpDDL-like，PpFY-like，PpCCT-like，PpBBX3-like，PpELF8-like，PpAMP1-like，PpHUA2-like and PpHUB1-like was a trend of reduce after rising first and reach the highest level in dormancy-release which consist end with the process of flower bud dormancy-release. The results speculated that they may be involved in dormancy-release of the flower bud.

Key words: nectarine, flowering gene, dormancy, RT-PCR, expression analysis